Vat dyes and process of making same.



E0 Drawing. 1

reruns VAT DYES AND PROCESS OF MAKING- SAME.

To all whom it may concern:

Be it known that I, RICHARD HERZ,Pl'1. D a subject of the King of Prussia, and a -res1- dent of Eysseneckstrasse 17 Frankfort-onthe-Main, Germany, have invented certain new and useful Vat'Dyes and Processes of Making Same, of which the following is a full description.

A series of new and very varied aromatic substances containing nitrogen, sulfur and chlorin in their molecule results, if an excess of disulfurdichlorid (S 01 is allowed to act on such aromatic aminocompounds and de rivatives thereof, which contain in their molecule at least one primary aminogroup and one free orthoposition thereto. The manufacture of these new substances forms the subject-matter of another application. I have now found that these new products can be converted into very valuable fast vat dyestuffs. For the manufacture of these coloring matters I proceed as follows:

The new products of reaction of an excess of disulfurdichlorid on aromatic aminocorn pounds and derivatives thereof are at first treated with water or dilute alkalis and are then condensed in an alkaline solution with monochloracetic acid, whereby products of condensation are formed, possessing the character of aromatic o-amino-carboxylic acids. These latter substances are then diazotized and in the diazo compounds thus produced, the diazo group is substituted by cyanogen, thus nitrile compounds are obtained. These nitriles are suitably treated with alkalis, alkaline sulfids, alkaline disulfids, or acids whereby they are saponified and simultaneously transformed into ring compounds, which by a further suitable treatment, preferably by heating them with dilute acids and subsequent oxidation produce the very valuable vat colors. These dyestuffs, containing sulfur in their molecule yield on animal and vegetable fibers shades varying from orange, red to purple, violet, brown and black, which are distinguished by their brightness and their unusual fastness to chlorin, severe washing, scouring, crossdyeing and bowking.

In order to illustrate the new process more fully the following examples are given:

Example 1.l00 kilos dry and wellground anilin hydrochlorid are heated in a suitable vessel fitted with a stirrer with. 5-10 times the uantity of disulfurdichlorid (S 01 to 50- 0 C. until a test can no Specification of Letters Patent.

Patented Get. 15, 191?.

Application filed June 16, 1915. Serial it 0. 34,471.

longer be diazotized and coupled. It is then diluted with an anhydrous, inert diluting agent, such as naphtha, benzene, ligroin, etc.,

-the separating body is removed by suction,

washed with one of the hydrocarbons mentioned, freed from any excess of sulfurchlorid that may adhere to it, and dried, preferably in a vacuum at as low a temperature as possible. 120 kilos of the product thus obtained are stirred to a paste with about four times the quantity of alcohol and while gradually stirringare introduced into 1000 liters alcohol of 50% and 250 kilos caustic soda lye 40 B. It is an advantage to add to this mixture about 50 kilos sodium hydrosulfite.

This mass is first cooled so that the term perature of the reaction may ,not exceed 80C., after some time the whole is gradually heated to 7 0 C. and the stirring is continued at this temperature until a test no longer becomes turbid, when diluted with water. 1%. neutral or slightly alkaline solution of kilos monochloracetic acid in about 250 liters water and 67.5'kil0s of caustic soda lye of 410 Be. are now added, the whole being heated for 2 to 3 hours at 70 to 80 C. Condensation being completed the alcohol is distilled ofi, the whole is filtered and the condensation product in solution may be directly used for the production .of the vat dyestufi.

If however it is desired to isolate the product of condensation the filtrate is acidified and boiled whereby a crystalline white body (presumably the inner anhydrite of the new compound) separates,.which is insoluble in water, dilute alkalis and acids.

For the further process it must therefore be saponified to the easily soluble alkaline salts, for instance by heating it with concentrated alkalis. For the production of the condensation product I may also proceed as follows:

Example 2.120 kilos of the product of reaction from anilin hydrochlorid and disulfurdichlorid (obtained as described above) are introduced while stirring well into about 3000 liters of water. The body goes first into solution, but after some time a new transformation product crystallizes out in leaflets of a slightly bluish color. The transformation being complete, which is indicated by the discoloration of the solution, 175 kilos of caustic soda lye 40 B. are slowly added while stirring well. The whole is heated to about 7 0 C. and then a neutral or slightly alkaline solution of 55 kilos monochlor acetic acid is added, heating and stirring being continued until the formation of the condensation product is finished.

Any slight quantities of precipitated impurities are filtered, the resulting solution may be used for the further process.

Example ormatz'on of the nitrile compound, and con/vertz'ng it into the oat dye st'wfi.

' The solution of the condensation product, obtained as described above, is charged with about 40 kilos sodium nitrite; the mixture is then gradually introduced while stirring well in dilute cold hydrochloric or sulfuric acid (for instance 200 kilos hydrochloric acid concentrated, 500 liters water and 500 kilosbonate, so that the solution thus obtained reacts, but weakly alkaline, filter it again and precipitate by acidifying.

The saponification of the nitrile so formed and the formation of the ringbody containing sulfur may be carried out by several methods. The followingis an advantageous process: 1

20 kilos of the nitrile are heated with 100 kilos sodium sulfid crystals and 20 liters water about -1 hour to to 100 (L The sodium salt of the new ring compound separates when heated in shining leaflets, the whole is then allowed to cool, diluted with a solution of common salt, and the separated precipitate filtered ofl'. i

In place of sodiumsulfid, sodium disulfid may be used with equally good results; the new ring compound is almost insoluble in such solutions in the cold, and therefore separates almost completely on cooling. The saponification of the nitrile and the formation of the ringcompound also takes place very easily and smoothly, when the nitrile is heated with concentrated alkali. If for instance 10 partsare heated with approximately 4 to 5 times the quantity of caustic soda lye of 20% to 25% NaOH for'ashort while only to 1 hour) on the water bath,

it is all changed to a crystalline pulp of the sodium salt of the new ring compound; when cold it is filtered ofi. The transformation of the latter into the leucocompound of the vat color is best done by boiling with dilute acids whereby carbonic acid and ammonia are split off. The sodium salt, obtained and described above, is dissolved in water, charged with dilute sulfuric acid and the acid solution is heated in therefiux condenser until the separationof the carbonic acid and the ammonia is complete. The whole is then allowed to cool and the precipitate is filtered off. For transformation into the red vat color, the precipitate is dissolved in dilute caustic soda lye, and a ourrent of air is passed through this solution until all the dyestufi' separates in crimson flakes. The alkaline solution of the leucobody may also be oxidized to the dyestuff by potassiumferricyanid, sodiumhypochlorid, sodiumperoxid and other suitable oxidizing agents. For instance to an alkaline solution of the leucocompound potassiumferricyanid is added until red flakes no longer separate.- The dyestuff is filtered off, washed 'out well and preferably used straightaway in paste form. 'When dried it is a crimson powder which dissolves in concentrated sulfuric acid with a greenish color. In hot nitrobenzene it dissolves with a crimson color and yellow fluorescence. In the alkaline hydrosulfite vat it dissolves with a yellowish color and dyes cotton crimson shades, which are distinguished by their excellent fastness to chlorin, light, severe washing and bowking. In exactly the same manner from the product of reaction, of disulfurdichlorid on o-toluidin a vat color dyeing pink shades of an unusual purity is obtained.

The product of reaction of disulfurdichlorid on paraxylidin, when worked up by the same process, yields a bluish pink vat color, whereas those from 'o-and p-amidophenolalkylether yield orange to red, those from oz and {5 naphtylamin brown, from acet m phenylenediamin, p-phenylenediamin and benzidin violet, blue and gray to blackish colors with similar properties and fastness.

In the saponification of the nitrile and its formed, I declare that what I claim is:

1. The herein described process for the manufacture of fast vat-dyestulfs, which consists in allowing an excess of disulfurdichlorid to act on aromatic aminocompounds and derivatives thereof, subjecting the 1,2ss,17o

products thus obtained at first to the action of dilute alkalis, preferably in the presence of a suitable reducing agent, then condenssame in an alkaline solution with monoch oracetic acid, diazotizing the products of condensation thus obtained, subjecting the diazocompounds produced to the action of cuprocyanid, saponifying and transforming the nitriles thus produced into ringcompounds by subjecting same to the action of alkalis, and finally converting the latter into vat-dyestuffs by subjecting same to the action of dilute acids while heating, subsequent oxidation.

2. The herein described process for the manufacture of fast vat-dyestufl's, which consists in allowing an excess of disulfurdichlorid to act on aromatic aminocompounds and derivatives thereof, subjecting the products thus obtained at first to the action of water, then condensing same in an alkaline solution with monochloracetic acid, diazotizing the products of condensation thus obtained, sub ecting the diazooompounds produced to the action of cuprocyanid, saponifying and transforming the nitriles thus produced into ringcompounds by subjecting the same to the action of alkalis, and finally converting the latter into fast vat-dyestuffs by subjecting same to the action of dilute acids while heating and by subsequent oxidat'ion.

3. The herein described process for the manufacture of a fast red vat-dyestufi' which consists in subjecting the product of reaction" of disulfurdichlorid and anilin at first to the action of dilute alkalis preferably in the presence of a suitable reducing agent, then condensing the same in an alkaline solution with monochloracetic acid, diazotiz; in the product of condensation thus obtamed, subjecting the diazo compound pro:

duced to the action of cuprocyanid, saponifying and transforming the nitrile thus produced into a ringcompound by subjecting the same to the action ofalkalis, and finally converting the latter into a fast red vatdyestufl by subjecting it to the action of dilute acids while heating and by subsequent oxidation.

4. The herein described process for the and by to the action of dilute acids whileheating manufacture of a fast red vat-dyestufi which consists in subjecting the product ofsreaction of disulfurdichlorid and analin at first to the action of water, then condensing the same in an alkaline solution with monochloracetic acid, diazotizing the condensation thus obtained, sub ecting the diazocompound produced to the action of cuprocyanid, saponifying and transforming the nitrile thus produced into a ringcompound by subjecting the same to the action of alkalis, and finally converting the latter into. a fast red vat-dyestuif by subjecting it and by subsequent oxidation.

- 5. The hereindescribed fast vat dyestuffs, derived from the products of reaction of an excess of disulfurdichlorid and aromatic roduct of I aminocompounds and derivatives thereof containing sulfur in their molecule, being in a dry state reddish to dark. colored powders,

insoluble in water, dilute alkalis and acids, sparingly soluble in alcohol, hot benzene and the usual organic solvents, difficultly soluble in hot nitrobenzene, with reddish to violet and brown colors, forming with alkaline hydrosulfite yellowish vats and dyeing animal and vegetable.fibers shades varying from orange, red to violet, brown and black, which are distinguished by their fastness to severe washing, scouring, bowking and chlorin.

6. The herein described new vat dyestufi,

derived from the product of reaction of di-,

sulfurdichlorid and anilin, being in a dry state a crimson powder, insoluble inwater, dilute alkalis and acids, difiicultly soluble in hot nitrobenzene with a bluish red color and yellow fluorescence, soluble in concentrated sulfuric acid with a greenish color forming with alkaline hydrosulfite a yellow vat and dyeing wool and cotton from such a bath crimson shades which are distinguished by their excellent, fastness.

In witness whereof I havehereuntosigned my name this sixth day of May, 1915, in the presence of two subscribing]- witnesses.

. RICHARD H RZ, PH. D. Witnesses:

JEAN GRU'ND, CARL GRUND. 

